* {
	margin: 0;
	padding: 0;
}

#box {
	width: 700px;
	height: 600px;
	border: 3px solid red;
	margin: 0 auto;
}

#box1 {
	/* border: 3px solid red; */
	width: 200px;
	height: 200px;
	float: left;

	position: absolute;
	/* 在body边框上进行偏移 */
	left: -30px;
}

#box2 {
	/* border: 3px solid blue; */
	width: 200px;
	height: 200px;
	/* margin: 0; */
	float: left;

	position: relative;
	/* 在所在的位置上进行偏移 */
	left: -30px;
}

#box3 {
	/* border: 3px solid pink; */
	width: 200px;
	height: 200px;
	/* margin: 0; */
	float: left;
}

img {
	width: 200px;
	height: 200px;
}